Vibrio cholerae O1 antigen

The **Vibrio cholerae O1 antigen**, also known as the lipopolysaccharide (LPS) O-specific polysaccharide, is a carbohydrate structure located on the outer membrane surface of *Vibrio cholerae* strains belonging to serogroup O1—the primary cause of epidemic/pandemic human cholera worldwide[2][4]. The structure consists mainly of repeating perosamine-containing oligosaccharides that define two main serotypes—Ogawa and Inaba—based on subtle chemical differences such as methylation patterns at terminal residues[5][7]. This surface-exposed molecule serves several key roles:\n\n> \"The *Vibrio cholerae* lipopolysaccharide O1 antigen is a major target of bacteriophages and the human immune system... [and] is critical for infectivity\"[1].\n\nIt acts as an essential virulence factor required for colonization/infection; it also functions as a receptor for certain lytic bacteriophages that specifically bind these structures during infection cycles.[3] The high immunogenicity makes it central in current vaccine formulations aiming to elicit protective antibodies capable of neutralizing diverse clinical isolates.[7] However, phase-variable expression controlled by genes such as manA/wbeL allows bacterial populations flexibility under selective pressure from host immunity or phage predation.[1]\n\nIn summary, **Vibrio cholerae O1 antigen/LPS-O-SP is an essential bacterial surface carbohydrate serving both pathogenicity/immune evasion functions—and remains one of microbiology’s best-characterized targets for diagnostics, therapeutics, phage therapy research, and rational vaccine design.

Other names

V. cholerae O1 antigenLipopolysaccharide (LPS) O1 antigenO-specific polysaccharide (O-SP) of V. cholerae O1Ogawa/Inaba serotype determinant (depending on structural variant)

For drugs/vaccines targeting this molecule:\n- Induction of protective antibody responses that recognize and neutralize V. cholerae by binding to its surface-exposed LPS/O-antigen, blocking colonization or promoting opsonophagocytosis[7].\nFor phages:\n- Adsorption/attachment via specific recognition of the O-antigen as a cell-surface receptor, leading to infection/lysis of bacteria[3].